Direct Chip Attach (DCA) on board is a concept that may allow significant cost savings by eliminating the package. However, board design rules have not scaled at the same rate as Controlled Collapsed Chip Connection (C4) bump pitch. Thus, in order to use DCA, the bump pitch of the chip die needs to be large enough to accommodate the board design rules, and that size bump pitch would be much larger than current technology allows for dies. This limits the number of interconnects that may be made using DCA.
As long as the bump pitch of the die is large enough to accommodate the board pad size and the line/space rules, DCA remains an attractive solution. However, in the System On Chip (SOC) area and in other high density interconnect applications, DCA is yet to be considered due to the mismatch between the C4 bump pitch scaling of current generation SOC die and the board pad size and line/space rules.